Table 2.
Outcome of radiofrequency ablation in the difficult and control groups n (%)
| Group | Number of patients | Number of tumors | Tumor diameter (cm) | Early necrosis | Local progression |
| Control | 88 | 170 | 3.1 ± 1.1 | 166 (97.6) | 12 (7.1)1 |
| Difficult | 382 | 473 | 3.4 ± 1.2 | 446 (94.3) | 60 (12.7)1 |
| Near large vessels or bile ducts | 87 | 95 | 3.5 ± 1.5 | 89 (93.7) | 10 (10.5) |
| Near peripheral structures | 232 | 291 | 3.4 ± 1.2 | 274 (94.2) | 42 (14.4)1 |
| Under liver capsule | 63 | 87 | 3.1 ± 1.4 | 83 (95.4) | 8 (9.2) |
| Total | 470 | 643 | 3.3 ± 1.3 | 612 (95.2) | 72 (11.2) |
1
Local progression rate in the difficult group was significantly higher than that in the control group (12.7% vs 7.1%, P = 0.046). Local progression rate in the subgroup of tumors near peripheral structures was significantly higher than that in the control group (14.4% vs 7.1%, P = 0.018).